JP4778330B2 - Chuck device - Google Patents

Description

  The present invention relates to a chuck device including a pair of clamping bodies capable of clamping an object to be clamped.

  In an industrial robot that automatically assembles an assembly composed of multiple parts, a chuck device is provided at the tip of the robot hand, and a workpiece (object to be clamped) is sandwiched between a pair of metal fingers in the chuck device. Assembling work or the like is performed (see, for example, Patent Document 1).

JP 2004-276193 A

  However, since each finger in the chuck device of Patent Document 1 is made of metal, it may be difficult to stably hold the workpiece. For example, when a work 91 having a certain hardness is sandwiched between metal fingers 90 as shown in FIG. 12 (a), the contact point between each finger 90 and the work 91 becomes a point contact. As shown in FIG. 12B, the work 91 may turn in an unexpected direction Rt.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a chuck device that can stably clamp an object to be clamped.

In order to solve the above-mentioned problems, the invention of claim 1 is a chuck device, comprising a pair of sandwiching bodies capable of sandwiching an object to be sandwiched, wherein the pair of sandwiching bodies is formed of a resin. And a changing means capable of changing a distance between the first holding body and the second holding body in a predetermined direction, and a second holding body made of metal. A clamping state detection unit that detects a clamping state of the object to be clamped by the pair of clamping bodies, and the change unit causes the pair of clamping bodies to pass through a clamping position that clamps the sandwiched object. It is movable between a fully open position that is the furthest away from each other and a fully closed position that is the closest to each other, and the holding state detecting means is movable within a predetermined range in the predetermined direction with respect to the first holding body. Provided, and the pair of sandwiching bodies A first electrode member facing the second sandwiching body while securing a first separation distance in the predetermined direction when in position, and a connection provided to the first sandwiching body and having conductivity The connection between the electrode and the second sandwiching body while ensuring a second separation distance shorter than the first separation distance in the predetermined direction when the pair of sandwiching bodies is in the fully opened position. A second electrode member facing the electrode, having conductivity and elastically deforming in the predetermined direction within a range longer than a difference between the first separation distance and the second separation distance; And an elastic member that urges one electrode member toward the second sandwiching body in the predetermined direction, and a connection electrode provided in a part of the first electrode member includes the pair of sandwiching bodies. Is in the fully open position by the elastic member The first separation distance is longer than the movement distance of the clamping body from the fully open position to the clamping position and shorter than the movement distance of the clamping body from the fully open position to the fully closed position; The second separation distance is shorter than the moving distance of the holding body from the fully opened position to the holding position, and the resin forming the first holding body has an insulating property.

Further, the invention of claim 2, in chucking device according to inventions of claim 1, wherein the chuck device is provided in a freely robot hand attached to and detached from the arm of the industrial robot.

According to invention of Claim 1 thru | or 2 , since a pair of clamping body is comprised by the 1st clamping body formed with resin, and the 2nd clamping body formed with a metal, it is clamped Can be held stably.

Furthermore, in the first aspect of the invention, since the first electrode member and the connection electrode are provided in the first sandwiching body formed of resin, the insulation state between the first electrode member and the connection electrode is reduced. Insulating members necessary for securing are not necessary, and the sandwiching state detecting means can be simplified.

In the invention of claim 2 , since the chuck device is provided in the robot hand which can be attached to and detached from the arm of the industrial robot, the workpiece falls when the workpiece clamped by the robot hand is transferred, and the workpiece And damage to other equipment can be prevented.

<Robot configuration>
FIG. 1 is an external view showing a main configuration of a robot 1 including a chuck portion 4 according to an embodiment of the present invention.

  The robot 1 which is an industrial robot is configured as a 6-degree-of-freedom vertical articulated robot in which three rotation degrees of freedom about a horizontal axis are arm-coupled between three degrees of freedom of rotation about a vertical axis. In the robot 1, it is possible to hold a workpiece such as a part and assemble the workpiece in the horizontal direction, and to assemble the workpiece in the vertical direction.

  The arm (arm) 2 of the robot 1 is provided with an attaching / detaching portion 21 to which the robot hand 3 can be attached / detached at the tip thereof. The attaching / detaching operation of the attaching / detaching portion 21 and the connecting portion 31 of the robot hand 3 having a specific structure for connecting to the attaching / detaching portion 21 will be described with reference to FIG. Here, FIG. 2A shows a state where the connecting portion 31 is not coupled to the detachable portion 21, and FIG. 2B shows a state where the coupling portion 31 is coupled.

  The detachable portion 21 at the tip of the arm 2 has a short cylindrical protruding portion 22 protruding along the central axis, and circular holes formed at a plurality of locations on the side surface of the protruding portion 22. A movable ball 23 having a diameter slightly larger than the circular hole is accommodated in each of the insides. Compressed air is supplied to the inside of the cylindrical protrusion 22 through the arm 2 so that the movable ball 23 can protrude and retract from the side surface of the cylindrical protrusion 22 by turning ON / OFF the supply of the compressed air. It has become.

  On the other hand, the attaching / detaching hole 31H provided in the connecting portion 31 of the robot hand 3 has a structure having an inclined surface 31a having a reverse taper so that the vicinity of the exit is narrowed, and the opening diameter thereof is the protruding portion 22 on the arm 2 side. Is compatible with the outer diameter of

  In the non-coupled state shown in FIG. 2A, the movable ball 23 is accommodated inside the protrusion 22. However, in the coupled state shown in FIG. 2B, the inclined portion 31a of the attachment / detachment hole 31H is formed by moving the movable sphere 23 by supplying compressed air and causing a part of the movable sphere 23 to protrude outside the projection 22. The movable sphere 23 is engaged with. As a result, the arm 2 and the robot hand 3 are connected. With the above operation, the robot hand 3 necessary for assembly work can be easily replaced. Further, when the supply of compressed air is stopped, the urging force to the movable ball 23 disappears, and the robot hand 3 can be removed by its own weight by pulling out the arm 2.

  FIG. 3 is an external view showing a main configuration of the robot hand 3.

  The robot hand 3 is connected to the main body part 32, the connecting part 31 having a short cylindrical shape as described above, a hand main body part (hereinafter also simply referred to as “main body part”) 32 connected to the connecting part 31. Four chuck portions (chuck devices) 4 are provided. Although these connection part 31 and the main-body part 32 are formed with resin, you may make it form these parts integrally.

  From the main body portion 32, the chuck portion 4 extends in four directions, and the chuck portion 4 has two finger portions 40.

  The finger portion 40 includes a pair of fingers 41 that function as a pair of sandwiching bodies. The pair of fingers 41 includes a finger (hereinafter abbreviated as “metal finger”) 41a formed of metal and a finger (hereinafter abbreviated as “resin finger”) 41b formed of resin. ing.

  A pipe line for supplying compressed air (driving air) to the air-driven chuck portion 4 is formed inside the connecting portion 31 and the main body portion 32. Here, since the connection part 31 and the main-body part 32 are formed with resin excellent in workability, it is easy to provide a pipe line in these. Hereinafter, these pipe lines will be described in detail.

  FIG. 4 is a view showing a cross section of the connecting portion 31 and the main body portion 32 as viewed from the IV-IV position in FIG. 3.

  The conduit 33 provided in the connecting portion 31 and the main body portion 32 is formed as a flow path of driving air that communicates from the end surface 31 e of the connecting portion 31 connected to the attaching / detaching portion 21 to the chuck portion 4.

  If the compressed air sent through the arm 2 is supplied to the inlet 30a of the pipe 33 by the pipe 33 having such a configuration, the compressed air can be sent from the outlet 30b into the chuck portion 4 through the pipe 33. Become. Thus, without providing a drive air pipe outside the robot hand 3, the pair of fingers 41 in the chuck portion 4 can be driven in the closing direction to hold the work as the object to be held.

  As described above, by providing the drive air conduit 33 inside the connecting portion 31 and the main body portion 32, piping for supplying drive air to the chuck portion 4 is not required, and the operation range of the robot 1 can be expanded. .

<Configuration of chuck part 4>
FIG. 5 is an external view showing the configuration of the chuck portion 4. Moreover, FIG. 6 is a figure which shows the side surface of the finger part 40 vicinity seen from the arrow Dv of FIG.

  The chuck unit 4 is provided with a clamping state detection unit SN that detects a clamping state of the workpiece by the pair of fingers 41. The configuration and operation of the sandwiching state detection unit SN will be described in detail below.

  The chuck portion 4 includes a moving member DRa to which a metal finger (second holding body) 41a is attached and a resin finger (first holding body) by compressed air supplied through the pipe line 33 (FIG. 4). ) A moving mechanism (moving means) DR capable of changing the distance between the fingers 41 to a moving direction (hereinafter also simply referred to as “direction”) Df by driving the moving member DRb to which 41b is attached. . With this moving mechanism DR, the pair of fingers 41 can move between a fully open position that is most separated from each other and a fully closed position that is closest to each other via a clamping position where the workpiece is clamped.

  A contact member 43 and a conductive electrode member (second electrode member) 44 are attached to the metal finger 41a in the finger portion 40 via an insulating member 42 as a support member. On the other hand, an electrode member (first electrode member) 45 and a connecting electrode 46 are attached to the resin finger 41b. Here, since the resin finger 41b is formed of a resin that acts as an insulator, an insulating member (such as the insulating member 42 related to the metal finger 41a) required to secure an insulating state between the electrode member 45 and the connecting electrode 46 is used. No need to be provided in the sandwiching state detection unit SN, and the sandwiching state detection unit SN can be simplified.

  Two screw holes 42a and 42b are formed in the insulating member 42 in parallel with the direction Df. The contact member 43 is screwed into the screw hole 42a from the outside of the insulating member 42. Further, the abutting member 43 has a lock nut 51 for defining the length of the abutting member 43 that is screwed into the screw hole 42 a and protruding to the inside of the insulating member 42 at a portion exposed to the outside of the insulating member 42. Are screwed together.

  The electrode member 44 has a structure that urges the movable pin 44b from one end of the main body 44a on which the screw portion is formed in a direction protruding in the axial direction of the main body 44a, and thus can be elastically deformed in the direction Df. . The electrode member 44 is screwed into the screw hole 42b from the outside of the insulating member 42, and the electrode member 44 screwed into the screw hole 42b is exposed to a portion of the electrode member 44 exposed to the outside of the insulating member 42. A lock nut 52 for defining a length protruding inside the insulating member 42 is screwed.

  A hole 50a and a screw hole 50b are formed in the resin finger 41b in parallel with the direction Df. The shaft portion 45a of the electrode member 45 passes through the hole 50a from the outside of the resin finger 41b. That is, the electrode member 45 is provided on the resin finger 41b so as to be movable within a predetermined range in the direction Df.

  A coil spring (elastic member) 53 that urges the electrode member 45 toward the metal finger 41a in the direction Df is externally fitted to a portion of the shaft 45a of the electrode member 45 that is exposed to the inside of the resin finger 41b. . One end of the coil spring 53 is fixed, for example, at a position Ps in the resin finger 41b, and the other end is in contact with an E ring 54 provided on the shaft portion 45a of the electrode member 45. On the other hand, on the other end side of the electrode member 45, a flange-like connection electrode 45b having conductivity in the shaft portion 45a is provided as a part of the electrode member 45.

  The connection electrode 46 has conductivity and includes a screw portion 46a and a head portion 46b. The connecting electrode 46 is screwed from the outside of the resin finger 41b. In the state where the finger 41 is in the fully open position as shown in FIG. 6, the connection electrode 45 b of the electrode member 45 is pressed against the head portion 46 b of the connection electrode 46, and this is because the electrode member 45 is made of metal by the elastic force of the coil spring 53. This is because it is biased toward the finger 41a.

  The hole 50a of the resin finger 41b and the hole 42a of the insulating member 42 are formed coaxially with respect to the direction Df. Therefore, the end surface of the electrode member 45 supported by the resin finger 41b faces the end surface of the contact member 43 supported by the insulating member 42 in the direction Df. On the other hand, the end surface of the connection electrode 46 supported by the resin finger 41b is also opposed to the end surface of the movable pin 44b of the electrode member 44 supported by the insulating member 42 in the direction Df.

  As shown in FIG. 6, in a state where the finger 41 is in the fully open position, the electrode member 45 and the contact member 43 on the metal finger 41a side have a certain distance (first separation distance) L1 in the direction Df. . On the other hand, the electrode member 44 and the connecting electrode 46 have a certain distance (second separation distance) L2 in the direction Df. Therefore, there is no conduction between the electrode member 44 and the electrode member 45 at the fully open position of the finger 41.

  Further, the first interval L1 is longer than the second interval L2, and the amount of elastic deformation of the electrode member 44 in the direction Df of the movable pin 44b is larger than the difference between the first interval L1 and the second interval L2. It is getting longer. Furthermore, the sum of the movement distances from the fully open position of each finger 41 to the clamping position (position where the workpiece is properly clamped) is shorter than the first interval L1 and longer than the second interval L2, The sum of the movement amounts of the fingers 41 from the fully open position to the fully closed position is longer than the first interval L1.

  FIG. 7 is a diagram illustrating a state where the finger 41 is in the clamping position.

  When the workpiece 9 exists in an appropriate posture between the metal finger 41a and the resin finger 41b, when each finger 41 is moved in the closing direction from the fully opened position shown in FIG. 6 by the moving mechanism DR, as shown in FIG. In addition, the workpiece 9 is clamped between the fingers 41 in an appropriate state, and each finger 41 stops at the clamping position.

  When the workpiece 9 is sandwiched, the contact member 43 and the electrode member 45 are not in contact with each other, and a constant gap Ga is maintained. However, the connecting electrode 46 contacts the movable pin 44b of the electrode member 44 and the movable pin 44b. Is pushed into the main body 44a.

  As described above, in a state where the workpiece 9 is properly clamped by the pair of fingers 41 at the clamping position, the electrode member 44 and the electrode member 45 are electrically connected via the connecting electrode 46.

  FIG. 8 is a diagram illustrating a state in which the finger 41 is in the fully closed position.

  When there is no workpiece between the metal finger 41a and the resin finger 41b, when each finger 41 is moved in the closing direction from the fully opened position shown in FIG. 6 by the moving mechanism DR, the finger 41 reaches the fully closed position.

  When the fingers 41 are fully closed, the connecting electrode 46 contacts the movable pin 44b of the electrode member 44 and the contact member 43 contacts the electrode member 45 and presses the electrode member 45 as shown in FIG. . As a result, the electrode member 45 moves against the urging force of the coil spring 53 in the outer direction of the resin finger 41b, so that the connection electrode 45b of the electrode member 45 does not come into contact with the head portion 46b of the connection electrode 46, and a certain amount An interval Gb is generated.

  As described above, in a state where the pair of fingers 41 cannot move the workpiece and move to the fully closed position, the electrode member 44 and the electrode member 45 are not electrically connected via the connecting electrode 46.

  Whether or not the workpiece 9 is properly clamped by the finger 41 is determined only by determining whether or not there is electrical conduction between the electrode member 44 and the electrode member 45 by the configuration and operation of the clamping state detection unit SN described above. Detection is possible. In the sandwiching state detection unit SN, since the resin fingers 41b are formed of an insulating resin, the insulating member necessary for ensuring insulation between the electrode member 45 and the connecting member 46 is not necessary as described above, and the sandwiching state detection unit SN is sandwiched. The configuration of the state detection unit SN can be simplified.

  Further, in the chuck portion 4, since one of the pair of fingers 41 is a metal finger 41a made of metal and the other is made of a resin finger 41b made of resin having a certain elasticity, the workpiece can be stably held. This will be described in detail below.

  FIG. 9 is a view for explaining clamping of the work 91 by the finger portion 40.

  When the workpiece 91 having a certain hardness is sandwiched between the finger portions 40, as shown in FIG. 9A, the resin finger 41b has a portion BN that bends elastically by the sandwiching force (gripping force) by the moving mechanism DR. Since the resin fingers 41b are elastically deformed in this way, the workpiece 91 can be held relatively softly, and therefore, the situation where the fingers 91 and the workpiece 91 are in point contact as shown in FIG. Thus, stable workpiece clamping is possible (FIG. 9B).

  In addition, in order to aim at the softer clamping with respect to a workpiece | work, forming both the fingers 41 in the finger part 40 with resin is also considered. However, in this case, since both fingers are deformed and the clamping force to the workpiece is reduced, it is difficult to stably hold the workpiece.

  As described above, in the finger portion 40 of the chuck portion 4, since one finger is made of metal and the other finger is made of resin, the resin finger can be reduced in weight and the workpiece can be soft-handled. Work can be clamped stably.

  For example, when a workpiece 92 (FIG. 10 (a)) having a taper for facilitating removal of a molded product from a mold is sandwiched, or a workpiece 93 (FIG. 10 (b)) that is easily depressed due to a hollow is sandwiched. Even in this case, the metal fingers 41a having a certain hardness can be softly sandwiched so as to be wrapped with the resin fingers 41b on the basis. In other words, in the chuck portion 4 of the present embodiment, it is possible to stably hold the workpiece without being affected by the shape and material of the workpiece (stiff or flexible). If such a chuck portion 4 is provided in the robot hand, it is possible to prevent the workpiece from dropping and damaging the workpiece and other devices when the clamped workpiece is transferred by the robot hand.

  Note that the chuck portion 4 of the present embodiment is not limited to the application to the vertical articulated robot shown in FIG. 1, but may be applied to another robot 6 shown in FIG. The robot 6 will be described below.

  The robot 6 is configured as a four-degree-of-freedom horizontal articulated robot in which one free-stretching degree of freedom in the vertical axis direction is provided at the tip of an arm joint having three degrees of freedom of freedom around the vertical axis. The robot 6 can hold a workpiece such as a component and assemble the component in the vertical direction.

  The arm 7 of the robot 6 is provided with an attaching / detaching portion 71 to which the robot hand 8 can be attached / detached at the tip thereof.

  The robot hand 8 includes a connecting portion 81 having the same configuration as the connecting portion 31 of the robot hand 3, a hand main body portion (hereinafter also simply referred to as “main body portion”) 82 connected to the connecting portion 81, and a main body portion. Two chuck portions 83 connected to 82 are provided. And this chuck | zipper part 83 has the finger part 84 which has a metal finger and a resin finger similarly to said finger part 40. FIG.

  Even in the robot 6 having such a configuration, the workpiece can be stably clamped similarly to the chuck unit 4 described above.

<Modification>
In the above embodiment, it is not essential that the metal fingers 41a and the resin fingers 41b have different shapes, and they may have the same shape (mirror symmetry).

  For the pair of fingers in the above embodiment, it is not essential to move both fingers to clamp the workpiece, and it is possible to clamp the workpiece by fixing one finger and moving the other finger. good.

  About the chuck | zipper part in said embodiment, not only what moves a space with a robot hand but what was fixed to space may be used.

It is an external view which shows the principal part structure of the robot 1 provided with the chuck | zipper part 4 which concerns on embodiment of this invention. 4 is a diagram for explaining an attaching / detaching operation between an attaching / detaching portion 21 of an arm 2 and a connecting portion 31 of a robot hand 3. FIG. FIG. 3 is an external view showing a main part configuration of a robot hand 3. It is a figure which shows the cross section of the connection part 31 and the main-body part 32 seen from the IV-IV position of FIG. FIG. 4 is an external view showing a configuration of a chuck portion 4. It is a figure which shows the side surface of the finger part 40 vicinity seen from the arrow Dv of FIG. It is a figure which shows the state which has the finger 41 in a clamping position. It is a figure which shows the state which has the finger 41 in a fully closed position. It is a figure for demonstrating clamping of the workpiece | work 91 by the finger part 40. FIG. It is a figure for demonstrating clamping of the workpieces 92 and 93 by the finger part 40. FIG. It is an external view which shows the principal part structure of the other robot. It is a figure for demonstrating clamping of the workpiece | work 91 by the finger 90 which concerns on a prior art.

Explanation of symbols

1, 6 Robot 2, 7 Arm 3, 8 Robot hand 9, 91 to 93 Work piece 21, 71 Detachment part 31, 81 Connection part 32, 82 Hand body part 4, 83 Chuck part 40, 84 Finger part 41 Finger 41 a Metal finger 41b Resin finger

Claims (2)

A chuck device,
A pair of clamping bodies capable of clamping the object to be clamped;
With
The pair of sandwiching bodies is composed of a first sandwiching body formed of resin and a second sandwiching body formed of metal,
Changing means capable of changing the interval between the first holding body and the second holding body in a predetermined direction;
Clamping state detection means for detecting a clamping state of an object to be clamped by the pair of clamping bodies;
And further comprising
By the changing means, the pair of sandwiching bodies is movable between a fully open position that is most separated from each other and a fully closed position that is closest to each other via a sandwiching position for sandwiching the object to be sandwiched.
The clamping state detection means includes
The first holding body is provided so as to be movable within a predetermined range in the predetermined direction. When the pair of holding bodies are in the fully open position, the first holding body is secured in the predetermined direction while securing the first separation distance. A first electrode member facing the two sandwiching bodies,
A connection electrode having conductivity and provided in the first sandwiching body;
Provided in the second sandwiching body, when the pair of sandwiching bodies are in the fully open position, facing the connection electrode while ensuring a second separation distance shorter than the first separation distance in the predetermined direction And a second electrode member having conductivity and elastically deforming in the predetermined direction in a range longer than a difference between the first separation distance and the second separation distance;
An elastic member for biasing the first electrode member toward the second sandwiching body in the predetermined direction;
And having
The connection electrode provided in a part of the first electrode member is pressed against the connection electrode by the elastic member when the pair of sandwiching bodies is in the fully open position,
The first separation distance is longer than the movement distance of the clamping body from the fully open position to the clamping position and shorter than the movement distance of the clamping body from the fully open position to the fully closed position, and the second separation distance. Is characterized by being shorter than the moving distance of the clamping body from the fully open position to the clamping position,
The resin forming the first clamping body has an insulating property . The chuck device according to claim 1,
  The chuck device is provided in a robot hand that can be attached to and detached from an arm of an industrial robot.

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